ARM and RISC on the BBC's Micro File (1987)

EdS · October 2, 2024, 4:26pm

In this short television program we get a brief interview with John Hennessy about the RISC philosophy (starts about 13:16 in the video) and we then get Fred Harris explaining about Acorn’s new RISC processor - ARM.

(Clearer version at the Computer Literacy Project minisite, possibly geoblocked, here)

“The evaluation system has been around for some time, priced at about £4500, but this is the first public showing of Acorn’s development machine. It’s about 35 times faster than an IBM PC and indeed it’s 20 times faster than this BBC Master here, as you can see from this demonstration. They are both calculating a 3D graph based on sines and cosines… If they could produce this RISC computer for, well, the cost of a Master, say £900, 20 times the speed for no extra cost, well, they’d have a very competitive machine.”

Presented by Fred Harris and Lesley Judd, this is a repackaged version of the BBC’s computer news programme Micro Live. Broadcast BBC One, 14 December 1987

EdS · April 23, 2025, 6:50am

Just found this video cued up in a long-neglected tab. But I notice that the Computer Literacy Project minisite includes several programs from the programme which you can run in-browser… here are two:

3D

Runs a line graphic that (on a BBC Micro) slowly reveals its shape, on a faster machine (such as an Acorn Risc Machine (ARM)) this would run very much faster

SGLTIK1

Runs a graphic that shows the principle of the RISC approach to handling instructions: In a conventional processor each clock tick may only partly process a complex instruction, the RISC chip averaging little more than just one clock tick to complete any of its (reduced, but optimised set of) instructions

The two floppy disk images can be found at

https://clp.bbcrewind.co.uk/jsbeeb/discs/CLP0071.ssd
https://clp.bbcrewind.co.uk/jsbeeb/discs/CLP0151.ssd

and can be used with most emulators, or unpacked using for example

The 3D program looks like this:

   10REM > 3D
   11REPEAT
   20MODE0:VDU29,640;512;:XS=2:YS=6*4
   30VDU23,1,0;0;0;0;
   40ON ERROR GOTO 190
   50A=640:B=A*A:C=512
   60Z=1/3:O=24/A:C=C/A
   70O%=&45
   80FORX%=0TOA STEPXS:S=X%*X%
   90P=SQR(B-S):M=-P*Z:N=M
  100PLOT69,-X%,M:PLOT69,X%,M
  110FORI=YS-P TOP STEPYS
  120R=SQR(S+I*I)
  130Y=I*Z+(R-A)*SIN(O*R)*C
  140IFY>M M=Y:GOTO170
  150IFY>N NEXT,:END
  160N=Y
  170PLOT69,-X%,Y:PLOT69,X%,Y
  180NEXT,
  181TIME=0:REPEAT UNTIL TIME>50
  185UNTIL 0
  190ON ERROR OFF
  200CLS
  210MODE1
  220VDU23,1,0;0;0;0;
  230*EXEC BASICBM

In case of an error - in practice, if you press Escape - it runs the BASICBM script, which is a series of basic benchmarks - the usual ones: